Designing From the Queries Backward

1. Normalization Answers a Question You Stopped Asking

Normalization optimizes for one thing: each fact is stored in exactly one place. That makes updates safe, because there is nothing to keep in sync, and it makes storage small, because nothing is duplicated.

Both of those were serious problems when the technique was developed and storage cost real money. One of them still matters.

The relational default that follows is familiar. Model the entities, normalize them, add indexes, and then write whatever queries the product needs